1.1 Earth's Crust in Motion

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Vocabulary

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Geologists: scientists who study the forces that make and shape the earth
Geology: the study of planet Earth
Constructive forces: forces that build up landmasses like mountains
Destructive forces: forces that slowly wear away mountains and surface such as what an ocean does
Continents: seven large landmasses on earth
Seismic waves: waves that move through the Earth's interior
Pressure: force pushing on a surface or area
Crust: layer of rock that makes up the Earth's outer skin
Basalt: dark, dense rock that forms the oceanic crust
Granite: rock with larger crystals that is less dense than basalt and makes up the continental crust
Mantle: layer of hot rock below the crust
Lithosphere: means "stone" and is the mantle and crust together
Asthenosphere: means "weak" soft rock material that can flow slowly
Outer core: layer of molten metal that surrounds the inner core
Inner core: dense ball of solid metal

Outline

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Science of Geology

• studying surface changes
  • surface always changing
• finding indirect evidence
  • cannot see inside earth
  • use seismic waves
    • speed of waves tells the material

Center of the Earth

• temperature
  • surface rock is cool
  • 20 meters/warmer
  • every 40 meters 1 degree celsius hotter
    • boy that's hot
• pressure
  • deeper you the greater the pressure

The Crust

• continental
  • granite
    • light colored rock
• oceanic
  • basalt
    • dark colored rock

The Mantle

• 40 meters below, you cross the crust's boundary and into the mantle.
• Crust and uppermost part of mantle are part of lithosphere
• Lower part of mantle is called asthenosphere
• Mantle is 3,000 meters deep

The Core

• Outer core
  • made of molten iron and nickel
  • behaves like a thick liquid
• Inner core
  • a dense ball of metal
    • under immense pressure so atoms can't expand and become liquid
• Misc.
  • core makes one third of Earth's mass, but only 15% of its volume
  • together slightly smaller than the Earth's own moon

Earth's magnetic field

• Currents in outer core force inner core to spin creating a magnetic field.